Mechanically operated. For the supervision of liquid media that flow through 1/2" to 8" tubes such as in oil, cooling or lubricant circuits. Can also be applied as protection against a lack of water. Installed vertically. Brass cap nut r3/4" with O-ring and connecting piece for soldering into a standard copper T-piece with 1/2" tee included. Switching capacity 24-250V, 5A.